Ibex Woolies Tech 1/4 Zip Base Layer Review

Temperature regulation is tricky in winter, especially for a sweat monster like me. I’m liable to sweat even on the most frigid days, which is a big no-no because then I end up cold and damp once the climb levels out. That’s why a comfortable, moisture-wicking base layer is critical during cold weather. This winter, I tested the Ibex Woolies Tech 1/4 Zip, a merino-blend base layer top designed to maximize mobility and temperature regulation.

Ibex Woolies Tech 1/4 Zip At a Glance

MSRP: $135
81% merino wool, 12% nylon, 7% elastane
Fabric origin / garment origin: Australia / Vietnam

Men’s Woolies Tech 1/4 Zip here.

Circumstances of Review

I received the top in November and tested it via early morning runs, day hikes, and casual wear in temperatures ranging from high 20s to low 50s Fahrenheit. I haven’t seen any snow yet this winter (thanks, climate change) but have encountered a few cool, rainy days. I’m five-foot-four, 130 pounds, and, as previously stated, an unstoppable sweat monster. I tested the base layer in “Deep Ocean” (blue) in a women’s small.

Intended Use

Hikers and trail runners who want to extend their outdoor activities into the shoulder season and winter will get the most out of this garment. The Woolies Tech base layer line is designed for active use. The fabric is a blend of merino wool, nylon, and elastane. The nylon gives the base layer more durability than pure merino, while the elastane gives it some stretch, which makes it more form-fitting and better for activity.

Yet the fabric is still 81 percent merino, a material lauded for its softness, odor control, breathability, and temperature management. Most backpackers will remind you that merino is better at staying warm when wet than synthetic fibers, making it great for overnight trips in cold weather. Merino is also naturally flame retardant, so you can cozy up to your campfire with fewer trepidations about accidentally setting yourself on fire. Although we still recommend exercising caution in that department.

Ibex also makes 100% merino Woolies, which are better suited to camp wear. These garments won’t have the durability and stretchiness of the Tech version, but they maximize the benefits of merino wool.

Ibex Woolies Tech 1/4 Zip Features

sleeve of blue ibex woolies tech 1/4 zip folded back on wrist to show flat interior seams

Rolled-back cuff shows anti-chafe flatlock seams and the optional basted thumb loop (diagonal bit).

Zip Neck

The Woolies Tech line includes leggings, long-sleeve crews, and the quarter-zip I tested. I wanted the quarter-zip specifically for its high collar and the flexibility to zip or unzip depending on the temperature. The zipper is generous—almost 10 inches long—and zips to right beneath the chin.

Nylon Core

Although the Pro-Tech fabric Ibex uses in these base layers is 81 percent merino wool, each fiber has a nylon core, which is more durable than pure wool. Pure merino has a tendency to stretch out and develop runs, holes, and loose threads over time. After four years, my other merino base layer is almost more patches than original fabric at this point.

I haven’t noticed any of those signs of wear so far in this base layer. I doubt the nylon core will do much to deter moths from munching on it, so I store this garment in a ziplock bag like the rest of my wool clothing.

Anti-Chafe Construction

The quarter-zip has raglan sleeves with off-shoulder seams. This allows for a broader range of movement and reduces the risk of chafing beneath backpack straps. Ibex also uses flatlock seams, which don’t stick up much, in the interest of minimizing rub.

Optional Basted Thumb Loops

This is a first for me. When I first received the shirt, I assumed the sewn-shut thumb holes were some bizarre vestigial feature carried over from an older design that had open thumb holes. But no. According to Ibex, they lightly sewed the loops shut so you can decide whether you want them.

Ibex Woolies Tech 1/4 Zip Pros

Excellent Temperature Regulation

The merino blend feels good against the skin and breathes well. It’s warm enough to motivate me to get outside even on cold mornings. And once I get moving and warm up, it wicks moisture and keeps me from overheating about as well as can be expected. (My powers of sweating are too great to be stopped by any mere “breathable” fabric, but this base layer does better than most.)


If you really want to know how durable this garment is, ask me again in a few years. However, after about six weeks of testing, it hasn’t stretched out or developed any holes or runs. The construction is solid, and I have a good opinion of Ibex products in general. The inclusion of nylon and elastane in the blend should help the base layer hold together over the years.

Optional Thumb Loops

close-up of wrist area of blue merino base layer with basted-shut thumb loops

I am Team Thumb Loops all the way. However, I know not everyone feels that way, so it’s nice that Ibex gives the consumer some flexibility.

If you like being able to keep the sleeves in place over your wrists, a seam ripper or sharp scissors will open up the thumb loops easily. Just note that once you’ve picked the seams, you can no longer return the shirt. If you don’t care for thumb loops, your cuffs can remain delightfully intact without that useless hole over the wrist to catch on things and let in cold air.

I appreciate the vote of confidence from Ibex in our judgment and seam-ripping skills.

Ibex Woolies Tech 1/4 Zip Cons

Shows Sweat

This is the one drawback of merino in general: unlike many synthetics, it shows sweat something fierce. I love the deep, jewel-tone blue of this shirt, but next time I would probably go with black to avoid the awkward pit stains.

Not Designed With Boobies in Mind

The shirt fits well everywhere except the chest and, to a lesser extent, the hips, where it tends to ride up. I like the close fit of this shirt, which is ideal for wicking moisture and keeping cold drafts out. It’s snug enough not to feel sloppy without being uncomfortably tight. However, those with larger cup sizes will probably want to size up. People with a less curvy figure will probably do just fine with the cut.

Overall Value

I wish the cut of the Woolies Tech 1/4 Zip fit me somewhat better, but I’m so impressed with its temperature regulation that I’ll probably keep wearing it anyway. At $135, this is not a cheap layer, although it’s comparable in price to similar garments. And I hope it will prove durable enough to last for years to come.

Shop the Women’s Ibex Woolies Tech 1/4 Zip

Shop the Men’s Ibex Woolies Tech 1/4 Zip

Comparable Products

Smartwool Intraknit 1/4 Zip

  • MSRP: $135
  • Materials: 52% wool/45% polyester/2% elastane/1% polyamide

Icebreaker Merino 260 Tech Half-Zip

  • MSRP: $135 – 150
  • Materials: Merino wool

The Ibex Woolies Tech 1/4 Zip was donated for purpose of review.

Affiliate Disclosure

This website contains affiliate links, which means The Trek may receive a percentage of any product or service you purchase using the links in the articles or advertisements. The buyer pays the same price as they would otherwise, and your purchase helps to support The Trek's ongoing goal to serve you quality backpacking advice and information. Thanks for your support!

To learn more, please visit the About This Site page.

What Do You Think?